Getting “science-driven” care for metastatic breast cancer

She had been traveling with her husband regularly from their home in Central Pennsylvania to Penn Medicine in Philadelphia, where he was being treated for leukemia and end-stage lung cancer. MJ also had a history of cancer: early-stage (IIB), hormone receptor-positive, HER2-negative breast cancer, diagnosed back in 2000. After surgery, chemotherapy, and radiation, her doctor prescribed tamoxifen but then switched her to an aromatase inhibitor (AI), which lowers estrogen levels by stopping an enzyme in fat tissue from changing other hormones into estrogen. By 2008, she had completed six years on AIs and thought she was, in her words, “home free.”

Since MJ was at Penn Medicine anyway, she decided to visit its clinic for breast cancer survivors. “I met a wonderful nurse practitioner there who asked, ‘Do you have any complaints?’ I said, well, I am getting older and I have arthritis,” she recalls. MJ had been seeing an orthopedic specialist and doing physical therapy for her symptoms. “Right away, I was sent for a CAT scan and an MRI and a biopsy, and it turned out I had bone metastases”—specifically, a lesion on her spine. It was difficult news to absorb as her husband prepared to enter hospice care.

MJ soon found herself under the care of a medical oncologist at Penn Medicine. Her doctor ordered a liquid biopsy, a test that uses a blood sample to identify any genomic mutations—alterations that develop in genes over time—to help inform her treatment decisions.

“They really had their ducks in a row!” MJ says. “I had no idea that care had reached this level—and how [these results] could play into decisions about what’s going to work and what’s not going to work.”

Knowing her mutations

Testing revealed that the cancer had developed an ESR1 (estrogen receptor-1) gene mutation, which is fairly common in women who have taken aromatase inhibitors for several years. About 40% of advanced HR+, HER2- breast cancers eventually develop this mutation, meaning the cancer will no longer respond to AIs. “There are many aromatase inhibitors out there, but if you have ESR1, it limits what you can use,” MJ says. “So I’m glad I had the test done.”

She says her oncologist “didn’t waste any time” and prescribed the hormonal therapy fulvestrant (Faslodex), which works differently than AIs because it is a selective estrogen receptor downregulator (SERD). SERDs bind tightly to estrogen receptors and break them down, blunting the effect of estrogen MJ had injections of fulvestrant into her buttock muscle and also took a CDK 4/6 inhibitor, palbociclib (Ibrance). That combination kept the cancer under control for four-and-a-half years.

Around 2021, MJ’s routine bloodwork and imaging scans—which she has every three months—began showing signs of progression. The cancer ultimately traveled to her liver and brain, which meant that she and her medical oncologist had to find a new treatment strategy. (In 2020, MJ had moved to suburban Philadelphia to be closer to Penn Medicine.)

“It is very science-driven,” MJ says, noting that she has had genomic testing twice since her progression, as well as a biopsy of the cancer tissue in her spine as well as her liver. “The test results can change over time—which I did not know,” she says. The cancer's ESR1 mutation status hasn’t changed, and tumor testing also revealed a mutation called PIK3CA, which could make her a candidate for the targeted therapy alpelisib (Piqray). But for now, her treatment plan has focused on getting areas of metastases under control.

“My doctor ordered the [liver] biopsy to check if maybe the cancer was HER2-low now,” and not truly HER2-negative. Research has shown that people with low HER2 results can be candidates for HER2-targeted therapies. Although the cancer's HER2 status hadn’t changed, “I appreciate the fact that [my doctor] always has her ear to the ground as to what might be coming.”

Staying informed and educating others

Over the past couple of years, MJ has been treated with the chemotherapy medicines capecitabine (Xeloda) and gemcitabine (Gemzar), as well as the CDK 4/6 inhibitor abemaciclib (Verzenio). In fall 2023, she started on sacituzumab govitecan (Trodelvy), which uses antibodies to deliver chemotherapy directly into cancer cells. Once again, genomic test results came into play: “There is a mutation that tells people if they are likely to have problems with Trodelvy—if they’re more likely to have blood count and GI (gastrointestinal) issues,” she says. MJ tested negative for that mutation, known as UGT1A1, which has been linked to more serious adverse events for those taking sacituzumab govitecan. People who have a specific variant in that gene need to be monitored more closely.

MJ also has had stereotactic radiation, a highly targeted form of radiation therapy, to her brain and spine. “It has been easier than I thought it would be,” she says.

What never gets easier, MJ says, are the routine PET scans, brain MRIs, and other imaging tests. “It doesn’t get easier because I have had a lot of drugs fail me. It’s always, ‘Oh, I sure hope this one is working!’”

But she also feels encouraged by the science: Since 2018, she has been involved with both Living Beyond Breast Cancer and Unite for HER, and she is part of a Philadelphia-area support group for people living with metastatic breast cancer. She and other members attend conferences and report back on what they learn. You can find them on Facebook at MetaRaise DENJPA.

“LBBC has been a great resource for hearing from some of the top-notch people in the country treating the disease,” she says. “And more conferences are saving space for advocates and patients. I am just grateful there are groups that can connect you with doctors and researchers who know what’s coming down the pipeline.”

She’s also aware of how much the approach to treatment has changed over the 23 years since she was first diagnosed, thanks in part to genomic testing—and she encourages all people with metastatic breast cancer to ask for testing and advocate for themselves.

“There is no dumb question! I am sure I have asked a million times, ‘If this doesn’t work, what are we going to do next?’ Even if it’s a blur at first, it is important to know if you have certain mutations,” MJ says. “You can use ‘Dr. Google’ and talk to others who have the same mutations.” That can help inform treatment choices, she adds.

Although treatments can have difficult side effects—MJ has experienced this herself with certain medications—she also feels that more attention is being paid to quality of life in metastatic breast cancer, especially over the past 5 to 10 years. “I am going into my seventh year with this disease, and just yesterday I went out and did some archery with my daughter. I did it last year so we decided to try it again!”

“I actually know what it means to live one day at a time,” she adds. “I’ve gotten to see my son marry, my daughter finish grad school, been on safari twice, and rescued my beloved dog, Bucatini.”